HIGH INTERNAL PHASE WATER/OIL EMULSIONS AND WATER/OIL/WATER EMULSIONS

Abstract: Stable, redispersible, high internal phase w/o emulsion concentrates having a weight ratio of water: oil from about 3.5:1 to about 19:1 are prepared under low shear using 0.5 to 3 wt.%, based on the weight of the oil phase, of an emulsifier that is a polyglycerol ester of polycondensed ricinoleic acid. These concentrates may be used, for example, as fat mimetics in the food industry, as clouding agents for beverages, and in cosmetic and pharmaceutical compositions. The concentrates may further be used in and includes w/o/w emulsion compositions.

Description: HIGH INTERNAL PHASE WATER/OIL EMULSIONS AND WATER/OIL/WATER EMULSIONS The present invention relates to lipid coated water droplets which can function as a fat mimetic in lowfat food products and are also useful as 5 clouding agents for beverages, and in cosmetic and pharmaceutical compositions. More particularly, the invention relates to a stable, high internal water phase water/oil (sometimes referred to as "w/o") emulsion concentrate of lipid coated water droplets which is readily dispersible lipid coated water droplets which is readily dispersible in water, and to a method 0 of preparing such a concentrate. The invention also relates to w/o/o (water/oil/water) emulsions prepared from such concentrates. The need to reduce fat in the American diet as expressed by the NIH, and the consumer demand for such products has resulted in extensive 5 reformulation of food products to reduce the lipid content. Reformation of food products requires inclusion of nonnutritive, nonlipid ingredients which impart the physical and sensory characteristics of food grade fats and oils. Two approaches- are: (1) to structure the aqueous phase with select soluble hydrocolloids and (2) to utilize micron size particulates to simulate oil 0 dispersed in water. It has been postulated that lipid coated particulates (either rigid or hydrogel forms) would represent an improvement over existing technology in the area of fat mimetics. Prior work to develop lipid coated solid particulates and/or lipid coated 5 aqueous gel spheres was only partially successful. One known problem is the rigidity and/or inflexibility of the particulates and/or gelled sphere in these prior art compositions. During regular food processing, the inflexibility of these rigid particulates could result in loss of lipid coating and subsequent functionality of the composition. Breakdown of the particles results in 0 generation of new nonlipid surface area which is contrary to the objective of lipid coated particles. Many food substances, such as salad dressings, mayonnaise, dairy drinks and other beverages are suspensions of oils or fats in water or in 5 aqueous mixtures. Many methods exist for reducing the fat content of these systems. Most involve structuring the external aqueous media with a thickening or gelling agent such as carrageenan, xanthan gum or a cellulosic, which provides the suspension with a creamy 'mouthfeel.' The disadvantage of such systems is that they rarely approximate the creamy, dense properties of a full fat system. Currently, the beverage industry has two types of clouding agents for such beverages as orange soda - ester gum and brominated vegetable oil. The U.S. Food and Drug Administration has limited the beverage content of ester gum to 100 ppm, while brominated vegetable oil content of beverages is restricted to 15 ppm. The European Economic Community (EEC) has banned the use of brominated vegetable oil and other synthetic clouding agents in beverages. There is thus a need for new, safe clouding agents in the beverage industry. See, for example, "Citrus Beverage Clouding Agents - Review and Status," P.C. Crandall, R. F. Matthews, and R.A. Baker, Food Technology. December, 1983. In U.S. Patents Numbers 4,632,840 (issued December 30, 1986), 4,590,086 (issued May 20, 1986), 4,988,456 (issued January 29, 1991) and 4,931 ,210 (issued June 5, 1990) all assigned to Meiji Milk Products Company, the inventors disclose stable w/o/w emulsions prepared using polyglycerol polyrincinolate emulsifiers. However, the disclosure is limited to w/o/w emulsions wherein the ratio of inner aqueous phase to oil phase does not exceed 3:1. These references, while dealing with a similar technology to that of the present invention, fail collectively to appreciate or teach that very stable w/o emulsion concentrates, having w/o ratios of 3.5:1 to 19:1 , can be prepared using as the emulsifier small amounts of a polyglycerol ester of polycondensed rincinoleic acid. S. Matsumoto, in "W/O/W - Type Multiple Emulsions, in Nonionic Surfactants. Surfactant Science Series, Vol. 23, pp 549-600 Editors M. J. Schick and F. M. Fowles, Marcel Decker, New York, 1987 disclose that adding glucose to the inner aqueous phase of a w/o/w emulsion causes water to migrate from the outer aqueous phase to the inner aqueous phase to thereby increase the ratio of inner aqueous phase to oil phase. However, on page 593 of that article, the authors further teach that the presence of electrolytes in the aqueous compartments impairs the stability of edible-type w/o/w emulsions. We have discovered that highly stable, redispersible, high internal phase w/o emulsions, having a weight ratio of water to oil in the range of about 3.5:1 to about 19:1 , can be prepared using as the primary emulsifier from 0.5 to 3% by weight, based on the weight of the oil phase, of a polyglycerol ester of polycondensed ricinoleic acid. An advantage of the compositions of the present invention is that they provide an equivalent oil surface area and volume to that of a full fat system but with a greatly reduced oil or fat content. The present invention provides a stable water in oil emulsion concentrate comprising from 80 to 95 weight percent of an aqueous phase, which may contain from 0 to 30 weight percent of a water soluble additive, dispersed in a continuous oil phase. This continuous oil phase comprises a lipid, typically a vegetable or mineral oil, that is liquid at 20°C-50°C and includes from 0.5 to 3% by weight, based on the weight of the lipid, of an emulsifier dissolved in the lipid. The emulsifier is a polyglycerol ester of polycondensed ricinoleic acid, having the formula (I) : OR 2 I R 1 O-(CH 2 -CH-CH 2 -O) n -R3 (I) wherein n is 2 to 12, and each R-| , R 2 , and R3 is independently H or polycondensed ricinoleic acid having the formula (II), provided that at least one of R- ] , R , and R3 is a polycondensed ricinoleic acid of formula (II) : -(CH 2 ) 5 CH 3 O I I H - [0-CH-CH 2 -CH=CH-(CH 2 ) 7 -C] m -OH (II) wherein m is 2 to 10. Another embodiment of this invention comprises a stable w/o/w emulsion having reduced lipid content which has particular utility comprising a concentrate as described above dispersed in an aqueous outer phase. In yet another embodiment, this invention provides a method for preparing a stable w/o emulsion concentrate as described above. The method comprises dissolving from 0.5 to 3 weight % of the emulsifier in an oil phase, heating the oil phase to a selected temperature in the range of 45 to 80°C, heating the aqueous phase to approximately the same selected temperature as the oil phase temperature, adding from 3.5 to 19 parts by weight of an aqueous phase to one part of the oil phase under moderate stirring at a rate of from 1 ,00 to 10,000 rpm and continuing stirring for from 1 to 5 minutes. In yet another embodiment, the present invention provides a novel method for stabilizing w/o/w systems by controlling the specific gravity of the water in the internal aqueous phase of the w/o emulsion concentrate used to form the w/o/w system. One application of this embodiment is the provision of novel clouding agents for beverages comprising w/o emulsion concentrates in accordance with the present invention. In order to obtain a fluid w/o emulsion suitable for redispersion as a lowfat mimetic, the oil phase must have a liquid surfactant dissolved in the oil and remain liquid at room temperature. A surfactant that is polymeric, soluble in the oil phase and which has an HLB (Hydrophilic-Lipophilic Balance) of 2-10, preferably 5 7 , will provide stability to the dispersed w/o emulsion. Also the surfactant must permit the incorporation of large amounts of water and be effective at relatively low concentrations (0.5 to 3%, preferably 1-2.5% based on the oil phase). The flexibility of the internal water droplet and the affinity of the polymeric surfactant for the surface of that droplet enables us to produce a superior fat mimetic - a stable lipid coated water droplet which simulates the physical and sensory properties of oil globules in water. The surfactant we employ in the compositions of the present invention is a polyglycerol ester of polycondensed ricinoleic acid having the formula (I) : OR 2 I Rl O-(CH 2 -CH-CH 2 -0) n -R 3 (I) wherein n is 2 to 12, and each R-j , R 2 , and R3 is independently H or polycondensed ricinoleic acid having the formula (II), provided that at least one of R-| , R 2 , and R3 is a polycondensed ricinoleic acid of formula (II) : -(CH 2 ) 5 CH 3 O I I H - [0-CH-CH 2 -CH=CH-(CH 2 ) 7 -C] m -OH (II) wherein m is 2 to 10. Preferably, the length of the glycerol chain is from 3 to 10, more preferably 2 to 3 glycerol units. Preferably the level of condensation of the ricinoleic acid chains is between 2 and 7. More preferably, m is 4 to 6. These esters are known in the art and are prepared by condensation of ricinoleic acid with glycerol. In general, polyglycerol polyricinoleate is prepared in the following steps. 1. Polyglycerol is manufactured by heating glycerol under vacuum with dilute sodium hydroxide as a catalyst. The duration of the reaction determines the degree of polymerization. Excess glycerol is removed by distillation. 2. Polyricinoleic acid is prepared by interesterification of castor oil fatty acids at controlled temperature in the absence of air. 3. The polyricinoleic acid is then condensed with the polyglycerol at temperatures near 200°C. Preferred polyglycerol esters of polycondensed ricinoleic acid for use in the compositions of this invention that are available commercially include Triodan R90 (manufactured by Grindsted) and Admul WOL (manufactured by Quest). The higher the degree of condensation, the less hydrophilic the surfactant. The longer the polyglycerol chain, the more hydrophilic the surfactant. Ideally, the surfactant will be sufficiently hydrophilic to anchor to the oil-water interface. To assure this, the glycerol chain is preferably between three and six units. The range of two to six appears optimal for the degree of ricinoleic acid condensation. The commercially available surfactants of this type mentioned above have glycerol chains of between 2 and 4 units and a degree of condensation of ricinoleic acid of about 4 to 6 units. The oil phase comprises a liquid lipid, preferably a vegetable oil or a mineral oil, and a surfactant of Formula (I). The vegetable oil may be selected from peanut oil, corn oil, soybean oil, canola oil, safflower oil, olive oil, cottonseed oil, coconut oil, palm oil, castorbean oil, butter oil and melted hydrogenated counterparts of the preceding. It may contain any triglyceride or combination of triglycerides. It may contain an animal fat such as lard, beef tallow and fish oil. It may contain hydrocarbons from petroleum distillates, mineral oil, long chain alcohols and acids or esters of long chain carboxylic acids and salts of long chain carboxylic acids for use in cosmetic emollients. Fat substitute oils such as carbohydrate fatty acid polyesters, malonate esters, esterified propoxylated glycerol, trialkoxytricarballate, polyorganosiloxanes and jojoba oils may also be used. The surfactant is dissolved in the oil at a concentration of between 0.5 and 3% by weight, preferably between 1 and 2.5% based on the weight of the oil. The oil phase may contain up to 30% by weight of "crystalline fats", i.e. lipids that are normally solid at room temperature, including animal fats, hydrogenated oils and other highly saturated fats. An additional non-ionic surfactant, for example, a surfactant selected from distilled monoglycerides or diglycerides, sucrose esters of fatty acids, citric acid esters of fatty acids, lactic acid esters of fatty acids, lecithin, acetylated lecithin, sorbitan esters of fatty acids, Diacetyl Tartaric Acid i esters of Mono and Diglycerides (Datem) emulsifiers, polysorbates, and fatty acid esters of propylene glycol, may be added to the oil phase or the water phase to enhance the water solubilizing capacity of the oil phase as needed in a particular application. (Ionic emulsifiers should be avoided, as they are detrimental to the stability of the high internal water phase w/o concentrates and w/o/w emulsions of the invention.) In addition, hydrocolloids such as maltodextrin, carrageenan, gelatin, xanthan gum, guar gum, alginate esters may be added to both aqueous phases (internal and external) or to either one to enhance stability by acting as an auxiliary emulsifier. If fats that melt at temperatures above room temperature ('hard" or "crystalline" fats) are to be used, they should not comprise more than 30 wt. % of the oil phase, and the mixture should be heated until all components are melted. In any event, prior to emulsification, the oil phase is preferably heated to between 45 and 80°C. The internal aqueous phase preferable includes from 0.1 % to 2% by weight of an electrolyte as hereinafter defined and may also contain one or more ingredients selected from antioxidants, flavoring agents, medicinal agents, nutritive agents, soluble fibers, colors, ultraviolet absorbers, additional non-ionic emulsifiers and other water soluble or dispersible compounds This aqueous phase may also contain one or more water gelling or water structuring or thickening agents, for example, starch, maltodextrin, gelatin, carrageenan, konjac, microcrystalline cellulose, cellulose ethers and esters, xanthan gum, gum arabic, agarose, glycerine, locust bean gum, pectin, propylene glycol, polypropylene glycol and the like. These structuring or thickening agents help to provide an enhanced oil-like sensory property which may be necessary in some applications. These structuring agents may be dispersed into the aqueous phase prior to emulsification or after the aqueous phase has been emulsified, depending upon the particular end use application. For example, if a hydrocolloid or other agent which must be activated with a catalyst is in the w/o concentrate, the catalyst may be added after the emulsion concentrate is prepared. Thus, if konjac is added to the aqueous internal phase, a small amount of base must be added to gel the konjac and this may be added after the emulsion concentrate is formed. ln the compositions of the present invention, the aqueous phase comprises between about 80% and 95% by weight of the total water-in-oil emulsion. Thus, the ratio of water to oil in the w/o concentrate is between about 3.5:1 and 19:1. The high internal phase w/o concentrate is prepared by introducing the aqueous phase to the oil phase under constant shear at between 45 and 80°C. The shearing device may be a homogenizer, a colloid milling device, a head or ball milling system, a Silverson mill-type mixer or a propeller blade mixer operating at rates of between 1 ,000 and 20,000 rpm. The preferred shearing device is ' the propeller mixer operated at 1 ,500-5,000 rpm, more preferably at 1 ,500-3,000 rpm. The emulsion may be prepared in one to two minutes. The emulsification is complete when the viscosity increases suddenly and dramatically from between 100 and 1 ,000 cp to >8,000 cp. The droplet size will decrease to the 1 - <5 micron range at this point, and no further decrease will be observed. The concentrate is then ready for redispersion into an external aqueous phase (to form a w/o/w emulsion). High internal phase ratios may be obtained in the w/o/w emulsions by adding electrolytes to the internal aqueous phase prior to emulsification and by forming the emulsion at lower internal phase ratios. The internal aqueous phase will swell to between 75% and 95% water, depending on the excess electrolyte concentration in the internal phase, after shearing for one to two hours in the external aqueous phase. The electrolyte may be univalent, such as NaCI or KCI, it may contain a divalent cation such as Ca 2+ or MG 2"1" , or it may contain a trivalent cation such as A|3 + . The higher the valence of the cation, the higher the swelling rate will be as well. For example, CaCI 2 or Na3Pθ4 will give a vastly increased swelling rate over NaCI. This phenomenon may be utilized to provide controlled release of flavors or medicinal compounds. The anion may be a halogen ion, an acetate ion, or a polyvalent anion such as PO^-, CO3 2 - or citrate, or a protonated form of such ion for example, HPO^-, H 2 Pθ4 _ . HCO3. HCit 2- , H Cit ' ' " , in which case the electrolyte will serve as a buffer in cases where necessary in an application, for example, to control microbial growth or to neutralize a flavor component or to prevent curdling in a dairy product. The presence of solutes in the internal and external phase may be manipulated to control the water amount in the internal phase. When there is an excess of simple electrolyte in the internal aqueous phase, water will migrate from the external phase through the oil layer into the internal phase. This will cause the oil continuous emulsion to swell. With excess salt (or other solute) in the internal phase, the emulsion may be added at 70 wt. percent water and during processing, increase to 85% water. This constitutes a doubling of actual emulsion volume (from 30% fat to 15%). When vinegar is added in excess to the external phase, swelling of the w/o emulsion occurs as well. This phenomenon can also be exploited to control the degree of fat replacement by water. This would be particularly useful in an oil/vinegar salad dressing. Internal water and salt, dyes and flavoring only very slowly cross the interface into the external aqueous phase when the emulsion contains less than 80% water in the internal aqueous phase. After 80% is exceeded, water and solutes cross the oil barrier in both directions finally attaining equilibrium. The rate at which the concentration of internal water phase in an emulsion containing less than 80% water (say 75%) will increase to in excess of 80% originally will depend on the amount of excess internal phase salt concentration (compared to that in the external aqueous phase). Diffusion of water from the external phase into the internal phase is rapid when a large concentration of solute, e.g. electrolyte, exists in the internal phase compared to that in the external aqueous phase. The internal phase may swell from 50% to 90% of the total emulsion weight when the electrolyte concentration difference (between internal and external aqueous phase) is several weight percent. On the other hand, if the excess concentration of electrolyte or any other internal phase solute is small (<2%), the amount of water uptake is less (an increase of 5-10 % of the total volume fraction of the internal phase) but transport of the electrolyte back into the external phase is extremely slow (<1% of the total in 3 days). In this case, the emulsion concentrate may also serve as a controlled release vehicle for water soluble flavors or medicinal compounds. The w/o emulsion concentrate of the invention is a high internal phase water in oil emulsion with a volume fraction of 0.67 - 0.95 as water and 0.05- 0.33 as the oil phase which ensheathes the water. As such, it is viscous but highly flexible such that it may be sheared to a very small doplet size and still retain its oil continuous characteristics without losing the internal water core. The emulsion does not conduct electricity. It possesses long term staiblity to phase separation. These emulsion concentrates are stable for greater than 8 months both as concentrate and in dispersed form. Because the emulsion concentrate is oil continuous, evaporation is retarded. The water core is so finely dispersed that microbial growth and activity is minimal. The emulsion has a sensory quality that mimics that of a high oil or fat containing system. The density of the emulsion depends largely on the composition of the internal phase. The internal phase may contain a hydrocolloid which will bind water and increase the density of the emulsion to the equivalent of (or greater than) that of the external phase. This increases the stability of the emulsion to creaming and will allow the emulsion to serve as a clouding agent. This is significant because of the current need for such systems for use in beverages requiring a high degree of opacity. Presently, brominated oils are used, which may be questionable from a health safety standpoint. It is also possible to increase the density of the emulsion by incorporating an electrolyte into the internal phase in high concentrations, but it must be taken into account that the internal phase weight fraction will increase, requiring a smaller beginning volume fraction. The droplets are somewhat hydrophobic and, like fats and oils, having a tendency to coalesce in the aqueous environment unless they are suspended by the incorporation in the internal aqueous phase of solutes, as mentioned above, or sheared to a very small size (10-100 microns), or a thickening or gelling agent is incorporated in the external phase, such as carrageenan in combination with calcium caseinate, in the case of a lowfat milk substitute, or a gum such as xanthan, propylene glycol alginate, locust bean gum, gum arabic and the like. The emulsions of the invention have a tendency to coat glass and adhere to glass and plastic surfaces to a greater degree than even fats and oils, and they are difficult to wash off a surface to which they are adhered. This can be overcome, if desired, by incorporating small quantities of gums or carrageenan into the external, continuous aqueous medium in which the oil-mimetic concentrate is dispersed. The aqueous dispersing medium for a w/o/w emulsion of the invention may contain any desired flavoring agent, salt, vinegar, protein, antioxidant compounds, emulsifier, viscosity enhancer, gelling agent structuring agent, hydrocolloid or dispersed crystalline material, milk, egg or other solids. The pH range is unimportant to the stability of the emulsion. The droplet size is a function of the shear method and rate during dispersion of the concentrate in the aqueous (outer phase) dispersing medium when preparing a w/o/w emulsion of the invention. It may range from 5 to 500 microns. The preferred range to provide optimal fat simulation is 5-50 microns, and will depend on the food system into which it is incorporated. The temperature of the concentrate and of the continuous medium is unimportant so long as 100°C is not greatly exceeded or sustained for a long period. The concentrate may be added at any desired concentration with respect to the aqueous dispersing medium. The higher the concentration level, the higher the degree of the organoleptic property of density or fattiness. For a typical oil/vinegar salad dressing, the level will be 10-20%, but may contain as little as 1-2% real fat. for an enhanced milk or cream, the level may be 4-8%, but the actual fat level may be as low as 0.5%, depending on the volume fraction of the internal phase of the concentrate. The following examples are presented to illustrate the practice of the invention. Example 1 : Formation of a high internal phase dispersible emulsion (4:1 w/o) The emulsion concentrate is formed by adding the aqueous phase to a surfactant containing oil phase using moderate shear at > 50°C, as follows: 1. 2 gm of polyglycerol ricinoleate (Admul WOL, Quest) is mixed into 98 gm of canola oil and heated to 60°C. 2. 4 gm of modified microcrystalline cellulose (Avicel® RC-591 , FMC) is added to 396 gm of distilled deionized water and dispersed with a Silverson mixer. The dispersion is heated to 60°C. 3. The solution from step 2 is added to the solution from step 1 at a rate of 150 ml/min under constant mixing using a Caframo propeller mixer at 2000 rpm. The emulsion is mixed for an additional 2 minutes after all the water is added. The emulsion is cooled to room temperature and mixed again at 2000 rpm for 2 minutes. The resulting emulsion can be redispersed in an aqueous solution containing a gelling hydrocolloid or other thickening agent, using a propeller mixer or a mill type mixer. The resulting emulsion possesses fat mimetic organoleptic properties similar to an o/w emulsion. Example 2: An inversion resistant oil continuous emulsion containing 15% Oil (6.7:1 w/o) An emulsion is formed which may be used in water rich food systems and is temperature stable as follows: 1. 2 gm of a distilled monoglyceride (Dimodan LSK, Grindsted) and 2 gm of polyglycerol polyricinoleate (Triodan R90, Grindsted) are added to 96 gm of an oil mixture containing 1/3 partially hydrogenated soybean oil and 2/3 canola oil. The mixture is heated to 60°C and stirred. 2 6 gm of Avicel® RC-591 MCC is added to 560 gm of distilled deionized water and mixed on a Silverson mixer for three minutes. The resulting dispersion is heated to 60°C. 3. The solution from step 2 is added to the solution from step 1 at the rate of 150 m/min under constant mixing with a Caframo mixer at 2,000 rpm. The emulsion is mixed for 3 minutes after the water is added. The emulsion is cooled slowly to room temperature and stirred for 3 more minutes at 2,000 rpm. The resulting emulsion is creamy, smooth and heat stable. Its viscosity decreases on heating but is recovered on cooling. It is a stable, heat thinning, high internal phase w/o emulsion. The emulsion may be redispersed into water or an aqueous mixture to form a w/o/w emulsion. Example 3 A low fat mayonnaise Mayonnaise is an oil-in-water emulsion. In this example, the oil phase is replaced by a w/o emulsion containing 80 wt. % water. 1. The w/o emulsion is prepared by adding 320 gm water at 60°C at a rate of 100 gm per minute to 80 gm of liquid soybean oil containing 3 gm of egg yolk solids and 1.6 gm of polyglycerol polyricinoleate (Triodan R90, Grindsted) also at 60°C under constant agitation with a lightnin mixer at 4,000 rpm. The emulsion is rapidly cooled to room temperature in an ice bath and mixed for 15 seconds with a lightnin mixer at 2,000 rpm. 2. 80 grams of the resulting emulsions then poured into 20 grams of an aqueous solution containing 0.25% xanthan gum (Kelco), 0.2% carrageenan (Gelcarin®, FMC), 1% salt, 3% sugar, 0.5% acetic acid and flavors (mustard, onion, etc.) and sheared for three minutes at 2,000 rpm on a lightnin mixer. The resulting w/o/w emulsion contains 16% fat (40 kcal/oz) rather than 80% fat (202 kcal/oz) as in a conventional mayonnaise. Example 4: A low fat oil-in-vinegar dressing French dressing contains coarsely dispersed oil at levels above 35% in an acidic aqueous medium. In this example, a w/o emulsion is used to replace the oil, resulting in an 80% fat reduction. 1. A w/o emulsion is prepared by adding 320 gm of water at 60°C to 80 gm of liquid vegetable oil + 1.6 gm of polyglycerol polyricinoleate at 60°C while agitating at 4,000 rpm with a propeller mixer. 2. The external water phase is prepared by mixing 100 gm of cider vinegar, 54 gm of water, 40 gm of sugar, 15 gm of salt, 15 gm of Worcestershire sauce, 20 gm of paprika, 3 gm of mustard, 3 gm of garlic, 3 gm of onion, 0.5 gm of white pepper, 2 gm of gum arabic, and 2 gm of dried egg yolk solids. 3. 160 gm of the w/o emulsion prepared in step 1 is added to the mixture of step 2 using moderate stirring under a Silverson mixer for 2 minutes. The resulting dressing contains 7% fat rather than 35% fat. Example 5: A lowfat milk with enhanced fat organoleptic characteristics In this example, a lowfat milk is treated with a high internal phase w/o emulsion to increase its creaminess as follows: 1. A w/o emulsion is formed by adding 320 gm of water containing 15% maltodextrin 15 DE at 60°C to 80 gm of butter oil containing 1.6 gm of polyglycerol ester of ricinoleate at 60°C under constant agitation with a propeller mixer at 3,000-4,000 rpm. 2. 50 gm of the resulting emulsion is then sheared into 950 gm of skim milk. The fat level of the milk will be 1 % rather than 4-5%, but will have a high surface area and hence, a more fatty mouthfeel, approximating that of whole milk. Example 6: An opacifier A high internal phase w/o emulsion containing a water binding hydrocolloid in the internal aqueous phase is stabilized gravitationally in a continuous aqueous phase soft drink as follows: 1. A w/o emulsion is prepared by adding 400g of a 16 wt.% aqueous maltodextrin solution to 100g of liquid vegetable oil containing 2% polyglycerol polyricinoleate at 60°C under constant shear with a propeller mixer at 4,000 rpm. The emulsion is sheared once more for one minute after cooling to room temperature. 2. One gram of the emulsion is then added, while shearing at 10,000 rpm, to 1 ,000 g of a carbonated orange drink containing 5% sugar, color and orange flavoring. The resulting soft drink will possess a stable, opaque appearance. Example 7: A lowfat shortening An effective shortening must comprise a plastic solid at ambient temperatures and must therefore contain solid fats. In this example, a shortening is prepared with 20% fat. To 78.4g of.a mixture of 65% coconut oil, 20% hydrogenated palm oil and 15% hydrogenated palm kernel oil is added 1.6 g of polyglycerol polyricinoleate (Triodan R90, Grindsted). After heating to 70°C, 320 g of an aqueous suspension of #5 microcrystalline cellulose (Avicel® RC-591, FMC) is added under constant agitation of 3,000 rpm with a propeller mixer, and the resulting emulsion is cooled to room temperature under constant stirring. The emulsion will have a plastic consistency between 20 and 30°C and will mimic the behavior of an ordinary shortening, i.e., it will possess a rapid meld profile and will set rapidly on a production line at reduced temperatures. The emulsion will actually be an o/w continuous emulsion in the solid state but will please invert to w/o upon melting and, therefore, provide function as a bakery shortening. Example 8: A nondairy creamer A w/o emulsion concentrate is prepared by adding 320 g of at 16% aqueous solution of maltodextrin 15 DE to 80g of liquid vegetable oil containing 2% polyglycerol polyricinoleate (Admul WOL, Quest) and 2% polysorbate 80 (Tween 80, ICI) in a Silverson mixer and shearing for two minutes. The resulting suspension can be added at a level of 1g/ounce to coffee or tea to provide whitening and a dense fat like mouthfeel. Example 9: A reduced fat ice cream The w/o concentrate is prepared by adding 320g of an aqueous phase, which contains 1-% glycerol, to 80g of a fat phase containing 1.6 gm of Admul WOL and 78.4g of milkfat, both phases being at 60°C. 10 g of the concentrate is dispersed into skim milk at 5,000 rpm in a Silverson mixer. The modified milk may then be sued to make ice cream in the standard way. The ice cream will have comparable flavor mouthfeel of a full fat ice cream. The glycerol lends freeze - thaw stability to the HIP emulsion. Example 10: A waterproof skincream for use as a sunblock and moisturizer is prepared as follows: Taking advantage of the adhesive, hydrophobic properties of emulsions, a skin cream is formed containing mineral oils of a variety of molecular weights as the external phase as follows. 400g water which contains 1% dispersed colloidal titanium dioxide as a UVA and UVB absorber is heated to 50°C and added in a Silverson mixer to 80 gm of an oil phase containing 78.4g mineral oil and 1% Triodan R90 (Grindstead). The ointment will not wash off in water without a strong soap and, because the emulsion is mostly water, it is a more effective skin moisturize than an ordinary oil. This is because the tendency of the oil to retard water evaporation from the skin is not as great as that of systems which contain large amounts of solubilized water. White the invention has been described herein with reference to specific embodiments, it is not limited thereto. Rather it should be recognized that this invention may be practiced as outlined above within the spirit and scope of the appended claims, with such variants and modifications or may be made by those skilled in this art.

Claims: 1. A stable water in oil emulsion concentrate characterized by from 80 to 95 weight percent of aqueous phase containing from 0 to 30 weight percent of a solute dispersed in a continuous oil phase which comprises a lipid that is liquid at 20°C-50°C having dissolved therein from 0.5 to 3% by weight, based on the weight of the lipid, of an emulsifier that is a polyglycerol ester of polycondensed ricinoleic acid having the formula (I) OR 2 I R 1 0-(CH 2 -CH-CH 2 -0) n -R 3 (I) wherein n is 2 to 12, and each R-j , R 2 and R3 is independently H or polycondensed ricinoleic acid having the formula (II), provided that at least one of R « | , R , and R3 is a polycondensed ricinoleic acid of formula (II): -(CH 2 ) 5 CH 3 O I I H - [0-CH-CH 2 -CH=CH-(CH 2 ) 7 -C] m -OH (II) wherein m is 20 to 10. 2. The concentrate of claim characterized in that emulsifier is a non- ionic block copolymer surfactant having an HLB of 2.5 to 7.5 3. The concentrate of claim 1 characterized in that n is an integer from 3 to 10, inclusive. 4. The concentrate of claim 3 characterized in that n is 2 or 3. 5. The concentrate of claim 1 characterized in that m is an integer from 2 to 7, inclusive. 6. The concentrate of claim 5 characterized in that m is 4 to 6. 7. The concentrate of claim 1 characterized in that said aqueous phase comprises water and up to 3% by weight, based on the weight of the water, of a solute. 8 The concentrate of claim 7 characterized in that said solute is an electrolyte. 9. The concentrate of claim 7 characterized in that said lipid phase comprises a vegetable oil. 10. The concentrate of claim 1 characterized in that at least one of said lipid phase and said aqueous phase further comprises a non-ionic surfactant. 11. The concentrate of claim 1 characterized in that said aqueous phase includes a thickening agent. 12. A stable w/o/w emulsion characterized in that aqueous phase comprises at least 80 weight percent of the inner emulsion which comprises a concentrate of claim 1 dispersed in an outer aqueous phase. 13. A method for preparing a stable emulsion concentrate of claim 1 characterized by dissolving from 0.5 to 3 weight % of said emulsifier in said oil phase, heating said oil phase to a selected temperature of 45 to 80°C, heating said aqueous phase to said selected temperature, adding from 3.5 to 19 parts by weight of said aqueous phase to one part of said oil phase under moderate stirring at a rate of from 1 ,000 to 10,000 rpm and continuing said stirring for from 1 to 5 minutes. 14. A beverage clouding agent characterized by a concentrate of claim 1. 15. A cosmetic composition characterized by a concentrate of claim 1. 16. A pharmaceutical composition characterized by a concentrate of claim 1.

Inventors: MCGINLEY EMANUEL J, YOUNG TIMOTHY J, MCGINLEY, EMANUEL, J., YOUNG, TIMOTHY, J.
Applicants: FMC CORP, FMC CORPORATION
Application year: 1994
Main classification: B01J13
IPC codes: A23C9, A23D7, A23D9, A23G3, A23G9, A23L1, A23L2, A61K8, A61K9, A61K47, B01F17, B01J13, C11C3